Police said they have arrested 29 people so far following Sunderland's 3-0 victory over Newcastle at St James' Park.
"Following the match there were a series of sporadic incidents of disorder in Newcastle city centre involving what appear to be Newcastle United supporters", Northumbria Police said in a statement.
The 29 people were arrested "in the main for public order type offences", the force added.
A football fan who was filmed attempting to punch a police horse has told ITV News that he is ashamed of his actions.
A police horse seen being punched by a football fan is "safe and well" this morning, its police force said.